T19977a.hs:11:7: error: [GHC-39999]
    • Could not deduce ‘Show a’ arising from a use of ‘f’
      from the context: Show [a]
        bound by the type signature for:
                   g :: forall a. Show [a] => a -> String
        at T19977a.hs:10:1-28
      Possible fix:
        add (Show a) to the context of
          the type signature for:
            g :: forall a. Show [a] => a -> String
    • In the expression: f x
      In an equation for ‘g’: g x = f x